In light of previous reviews, as soon as I opened the box I stuck each one into a breadboard and ran a basic test. I can't say if they meet all specs, but they work in the main modes, at least at close range, with no visible differences from other comparable modules purchased in the past. Also, all the boards I received had QFN ICs on board, none of the epoxy blobs that anyone has supposedly gotten in the past. This allowed me to graft one of the chips onto a custom PCB using a hot air tool, where it worked well.
π‘ Izokee ESP-01 Serial WiFi Transceiver Module with USB Converter, Compatible with Arduino
8 Review
π SFP Copper RJ45 Transceiver Gigabit Module 1000Base-T Compatible: Cisco GLC-T/SFP-GE-T, Meraki MA-SFP-1GB-TX, Mikrotik, Ubiquiti, Netgear, D-Link, TP-Link, Broadcom - 100 Reach, 2 Pack
8 Review
10GBase-T SFP+ Transceivers, 10G Copper RJ-45 SFP+ CAT.6a, up to 30 meters, π Cisco SFP-10G-T-S Compatible, Ubiquiti UniFi UF-RJ45-10G Supported, Fortinet, Netgear, D-Link, Supermicro (Pack of 2)
9 Review
MikroTik S+RJ10 Ethernet Transceiver
10 Review
π StarTech.com NETRS232 Serial to IP Ethernet Device Server - DIN Rail Mountable - Serial Device Server - Serial Over IP Device Server (Black)
4 Review
π StarTech.com NETRS2321P: 1-Port RS232 to Ethernet IP Converter, Serial over IP Device Server - Black
5 Review
UGREEN USB 3.0 Ethernet Adapter Hub with RJ45: Fast Gigabit Ethernet Converter, 3 Ports USB 3.0 Hub Compatible for MacBook, iMac, Surface Pro, Chromebook, Laptop, PC
11 Review
π uni USB C Hub with Ethernet Adapter, 4K HDMI, Gigabit Ethernet, and 3 USB 3.0 Ports for MacBook Pro, iPad Pro, XPS
11 Review